1. Technical Field
The present invention relates to a head unit that is provided with a plurality of unit heads that eject a liquid from a nozzle, and a liquid ejecting apparatus.
2. Related Art
A liquid ejecting apparatus is an apparatus that is provided with a liquid ejecting head that is capable of ejecting a liquid as liquid droplets from a nozzle, and that ejects various liquids from the liquid ejecting head. As a representative example of this kind of liquid ejecting apparatus, it is possible to include an image recording apparatus such as an ink jet type recording apparatus (printer) that is provided with an ink jet type recording head (hereinafter, referred to as a recording head) and performs recording by ejecting a liquid ink (in the form of ink droplets) from a nozzle of the recording head. Further, in addition to the above, liquid ejecting apparatuses are used in the ejecting of various types of liquid such as coloring materials that are used in color filters for liquid crystal displays and the like, organic materials that are used in organic EL (Electro Luminescence) displays, and electrode materials that are used in electrode formation. Further, liquid ink is ejected in recording heads for image recording apparatuses, and solutions of the respective color materials of R (Red), G (Green) and B (Blue) are ejected from color material ejecting heads for display manufacturing apparatuses. In addition, liquid electrode material is ejected from electrode material ejecting heads for electrode formation apparatuses, and solutions of living organic matter are ejected from living organic matter ejecting heads for chip production apparatuses.
In a printer such as that mentioned above, a single recording head that ejects ink is configured as a unit head, and there are printers in which a single head unit is configured by arraying a plurality of such unit heads (for example, refer to JP-A-2012-183758). Each unit head introduces ink from an ink supply source (such as an ink cartridge) into a pressure chamber (pressure generation chamber), generates a pressure variation in the ink inside the pressure chamber by operating pressure generation units such as a piezoelectric element or a heater element. Further, each unit head is configured to eject the ink inside the pressure chamber (in the form of ink droplets) from a nozzle (formed as an opening in a nozzle surface) using the pressure variation. In addition, a head unit such as that described above is provided with a transmission substrate that sends a drive signal to each of the pressure generation units.
In recent years, the miniaturization of head units has been progressing. For example, head units are being developed in which a plurality of unit heads (in which two nozzle rows are provided) are arrayed on both surface sides of a transmission substrate that forms a base of a wiring substrate. Each head unit is provided with a flexible cable, one end of which is connected to the transmission substrate. Further, a fluid channel that is in communication with each nozzle row is provided on both sides of the flexible cable with the flexible cable interposed therebetween. That is, a fluid channel that is on the transmission substrate side and a fluid channel that is on a side that is opposite thereto are provided in each unit head with the flexible cable interposed therebetween. If such a configuration is adopted, since the fluid channel that is on the transmission substrate side is disposed between the transmission substrate and the flexible cable, a contact portion of the transmission substrate and the flexible cable becomes an obstruction in cases in which the fluid channel on the transmission substrate side comes into contact with the fluid channel on the upstream side. In particular, since the width of the flexible cable with respect to the unit head becomes relatively larger if unit heads are miniaturized, the arrangement of a fluid channel that comes into contact between the fluid channel on the upstream side and the fluid channel of the unit head becomes complicated, and the connection of fluid channels is more difficult.